Painful fibromuscular disorders are common causes of pain and disability. In particular, fibrositis (also known as fibromyalgia) is a type of fibromuscular disorder that is a frequent cause of debilitating pain arising within muscles or muscle-tendon and tendon-bone junctions. Fibrositis is seen more frequently in women and is characterized by four constant features: pain, stiffness, fatigue and non-restorative sleep. In contrast with most rheumatic disorders, fibrositis rarely is responsive to corticosteroids and non-steroidal anti-inflammatory drugs. The only area in which medications are currently of proven value is in management of the associated sleep disorder.
I have discovered that tricyclic anti-depressants, usually prescribed orally for relief of mental depression or applied topically to the skin to relieve itching in dermatitis as described in my prior U.S. Pat. No. 4,395,420, are surprisingly effective at relieving or moderating the pain, stiffless, fatigue and sleep disorder associated with fibromuscular disorders such as fibrositis when applied topically. These compounds include the pharmaceutically acceptable salts of the tricyclics. The term pharmaceutically acceptable salts, as used herein, refers to the physiologically acceptable acid addition salts such as the hydrochloride, hydrobromide, hydroiodide, acetate, valerate, oleate, etc. Doxepin, amitriptyline and imipramine respectively are the tertiary amine derivatives of dibenzoxepin, dibenzoycloheptadiene and dibenzazepine wherein the nitrogen atom is connected to the ring structure by a three carbon aliphatic chain and the tertiary amine has two carbon atoms attached thereto in addition to the aliphatic chain.
The present invention relates to a method for topically treating fibromuscular disorders such as fibrositis. The principal object of the present invention is to apply topically divided doses of tricyclic anti-depressant compounds traditionally employed systematically for treatment of mental depression to relieve pain, stiffness, fatigue and sleep disorders characteristic of fibrositis. It is speculated that alleviation of the associated sleep disorder may arise either from relief of the pain and stiffness that prevented restful sleep, and/or from the sedative effect that these compounds are known to provide when administered systemically.
This and other objects of the present invention may be more readily understood when considered in conjunction with the following detailed description and examples.